1. Field of the Invention
The present invention relates to a substrate structure in which a mounted component is disposed between substrates arranged side by side.
2. Description of the Related Art
Endoscopes are used in, e.g., medical fields and industrial fields. Examples of the endoscopes include what are called electronic endoscopes with an image pickup apparatus incorporated in a distal end portion of an insertion portion thereof. For the electronic endoscopes, there is a demand for image quality enhancement, and thus, e.g., an increase in number of pixels in image pickup devices is being pursued.
In the endoscopes, there is a long transmission passage connecting the image pickup apparatus incorporated in the distal end portion of the insertion portion and, for example, a video processor, which is an external apparatus. Therefore, a relay substrate that amplifies a drive signal for an image pickup device is provided inside the endoscope operation portion to enhance the image quality and reduce diameters of signal cables inserted inside the insertion portion.
Inside the endoscope operation portion, many incorporated endoscope components are inserted in addition to the signal cables. Examples of the incorporated endoscope components include, e.g., a light guide fiber bundle for supplying illuminating light, an air feeding tube included in an air feeding conduit, a water feeding tube included in a water feeding conduit, a dual-purpose tube that serves as a suction conduit and a treatment instrument conduit, and bending wires that make a bending portion perform a bending operation.
Thus, the relay substrate is configured to have a small size. As a result, as illustrated in FIG. 1, a spacing between a first substrate 101 and a second substrate 102 included in a relay substrate is reduced. Then, it is necessary that a plurality of signal wires 103 be disposed in the reduced space S in such a manner that the plurality of signal wires 103 are prevented from electrical contact. However, a technique for disposing the plurality of signal wires 103 in the reduced space S requires a lot of skills.
Note that reference numeral 104 denotes a first connector mounted on the first substrate 101, reference numeral 105 denotes a second connector mounted on the second substrate 102, reference numeral 106 denotes a first signal cable, reference numeral 107 denotes a second signal cable, and reference numeral 108 denote a cable retainer member. The first signal cable 106 includes a plurality of signal wires 109 connected to connection portions (not illustrated) provided on the first substrate 101. The second signal cable 107 includes a plurality of signal wires 103 connected to connection portions (not illustrated) provided on the second substrate 102. The cable retainer member 108 is a member for attaching the second signal cable 107 to the second substrate 102.
Japanese Patent Application Laid-Open Publication No. 2009-158606 discloses a technique for forming an electronic device so that the electronic device can conform to high-density mounting and ensure an electromagnetic shielding effect.